Weft straightening apparatus



June 29, 1954 G. B. WOOD, JR

WEFT STRAIGHTENING APPARATUS 2 Sheets-Sheet 1 Filed Jan. 23, 1952 n d ummh June 29, 1954 B. WOOD, JR

WEFT STRAIGHTENING APPARATUS 2 Shee'ts-Sheet 2 Filed Jan. 23, 1952 Hi ll? Patented June 29, 1954 UNITED STATEfii ,tznai ZZ EtTENT OFFICE WEFT STRAIGHTENING APPARATUS Application January 23, 1952, Serial No. 267,766

6 Claims. l

This invention relates to improvements in weft straightening apparatus. More particularly it provides improvements in multiple roll weft straighteners whereby skewed weft threads in textile fabrics may be restored to proper perpendicularity to the warp threads with assurance that a fabric sheet passing through my improved weft straightening apparatus will leave the apparatus in a path substantially in alignment with the path of approach of the sheet to the apparatus.

In the processing of textile sheet materials, it frequently happens that the weft threads of the fabric become displaced or skewed out of their initial proper perpendicularity to the warp threads and various weft straightening devices are available for restoring them to proper relation to the warp threads. A usual Weft straightening procedure is to cause the fabric sheet to be acted upon by one or more tiltable rolls which may be tilted selectively in either of two opposite directions to increase the length of the path of travel of either selvage relative to the path of travel of the other selvage.

Heretofore, available tiltable roll'weft straighteners have acted on travelling webs with the desired web straightening action but the corrective effect frequently has been accompanied by lateral displacement of the web out of its proper path of travel. While it has been possible to avoid such lateral displacement of an engaged web with weft straightening apparatus as disclosed in Patent No. 2,343,328, granted March '7, 1944, to John D. Robertson and Joseph L. Dube, especially when only a single tiltable roll has been employed, certain rather precise relationships of parts have been requisite in order to avoid lateral displacement of a web and it frequently is not practically feasible to maintain the required relationships. Actually, it has proved desirable in a majority of cases to employ cloth guiders for restoring a web to its proper path after the web leaves any of the prior weft straighteners and preparatory to passage of the web into tenter frame or other processing mechanism.

When a travelling sheet or web passes around a tilted roll the web will not move laterally along the roll so long as the direction of advance of the web to the tilted roll is perpendicular to the roll axis. However, if the web advances to the tilted roll in a direction which is not at ninety degree angles to the roll axis, the web has a natural tendency to crawl along the roll until its direction of advance to the tilted roll is at right angles or perpendicular to the roll axis.

Lateral displacement of a travelling sheet which passes over a tilted roll is due to the natural tendency of the sheet to crawl along the roll until it approaches the tilted roll at right angles to the roll axis. When the wrap of the sheet around the roll is such that the sheet will not slip along the roll due to the tilt, the sheet will crawl along the roll until its approach is perpendicular to the roll axis.

Heretofore, this natural crawling of a sheet along a tilted roll has resulted in the sheet leaving the weft straightener substantially out of alignment with the path in which the sheet comes to the weft straightener.

It is among the objects of the present invention to provide weft straightener apparatus wherein the lateral crawling of a sheet in one direction along a tilted roll is neutralized by a substantially equal lateral crawling of the sheet in the opposite direction along one or more other tilted rolls. According to the invention, a fixed lead-on guide roll and at least one other fixed guide roll are associated with at least two tiltable rolls in relative positions such that a travelling sheet passing alternately around tilted and fixed rolls crawls in counteracting directions and amounts along the tilted rolls. If only two tiltable rolls are employed, the fixed lead-on roll will be located to occasion crawl of the sheet along the adjacent tilted r011 substantially equal to the crawl of the sheet in opposite direction along the other tilted roll. If three or more tiltable rolls are employed, the lead-on roll will be located to occasion crawl of the sheet along the adjacent tilted roll substantially equal to the sum of the crawls of the sheet in the opposite direction along the other tilted rolls.

A further object of the invention is to provide weft straightening apparatus wherein fixed rolls and tiltable rolls are relatively associated to produce neutralizing lateral crawl of a travelling sheet in opposite directions along difierent tilted rolls thereby to attain substantial alignment of the paths of travel of a sheet entering and leaving the apparatus, one of the fixed rolls being a lead-on roll which may be selectively located at any of a plurality of predetermined positions depending upon the number of tiltable rolls which are to participate in any particular weft straightening operation.

It is, moreover, my purpose and object generally to improve weft straightening mechanisms and weft straightening procedures and results.

In the accompanying drawings:

Fig. l is a diagrammatic representation of a tiltable roll weft straightening apparatus embodying features of the invention, with a textile sheet threaded therethrough and travelling in the direction of the arrows, the tiltable rolls being shown in their neutral non-tilted positions;

Fig. 2 is a top plan view of the apparatus and sheet of Fig. 1; and

Figs. 3, 4 and are cross-sectional views respectively on the lines 33, 4-4 and 55 of Fig. 1, but showing the tiltable rolls in tilted positions.

Referring to the drawings, a sheet II! of textile fabric, or the like, travels in the direction of the arrows over the fixed lead-on guide roll l2 to a tiltable roll I4 which is rotatably mounted in a tiltable frame I6. As herein represented, there are three similar tiltable rolls I4, I8, mounted in the tiltable frame I6, all tiltable with the frame as a unit about the axis of pivotal supports 22, 24 at opposite ends of the frame. Also, as shown, three fixed guide rolls 26, 28, are mounted in parallelism below and in staggered relation to the tiltable rolls in positions such that the sheet Ill, when frame I6 is in its neutral position of Fig. 1, travels substantially in a vertical plane from the tiltable roll Ill to and around the guide roll 26, whence it travels generally in a vertical plane from guide roll 26 to and around tiltable roll I8. The sheet travels similarly to and around the fixed and tiltable rolls 28, 2G and 30, leaving the weft straightener apparatus from the latter mentioned guide roll 30.

The frame I6 may be selectively tilted, more or less, in either direction about the axis of its pivotal supports 22, 24 by any suitable mechanism which may be manually controlled but which preferably will be automatically responsive to skew detecting means which detects a skewed condition of the weft threads and effects a proper tilting of the weft straightening tiltable roll or rolls. As herein represented, a screw 32 has gear connection at 34 to the shaft of a reversible electric motor 36 which operates in one direction or the other in response to detection of skew by the skew detecting means (not shown). The screw 32 is threaded through a nut 38 which is loosely but non-rotatably mounted in a short section 40 of channel iron secured to one end of tiltable frame It to one side of its pivotal axis. When motor 36 operates in one direction, the frame tilts in one direction about its pivotal axis, and when the motor operates in the opposite direction, the frame tilts in the other direction about its pivotal axis.

When frame I6 is in its neutral position of Figs. 1 and 2, with its rolls I4, I8, 20 parallel to the fixed guide rolls 26, 28, 30, the sheet I0 passes through the apparatus without any lateral displacement and the paths of approach of the sheet to and departure of the sheet from the apparatus will be substantially in alignment, as shown in Fig. 2.

Figs. 3-5 show the frame I 6 and its rolls I4, I8, 20 tilted clockwise about the pivotal axis of the frame. Fig. 3 is a View on line 3-3 of Fig. 1 showing how the sheet coming to the tilted roll I 4 crawls laterally to the left along roll I4 until its approach is perpendicular to the tilted roll axis, and showing the sheet passing downward to the fixed guide roll 26 on which the sheet is displaced laterally to the left from its path of approach to the upper lead-on guide roll I2.

Fig. 4 is a view on line 44 of Fig. 1 showing how the sheet, in traveling upward from roll 26 to the second tilted roll I8, crawls laterally to the right until its approach to tilted roll I8 is perpendicular to the axis of roll IS. The sheet passes downward from tilted roll I8 to the second guide roll 28, as shown in Fig. 5, and passes upward from roll 28 to the third tilted roll 20 with a further crawling to the right into perpendicularity to the axis of tilted roll 20. The sheet passes downward from tilted roll 20 to and around the third guide roll 30 from which it proceeds in a path substantially aligned with the path of approach of the sheet to the lead- On guide roll I2.

In the accomplishment of my novel results, it is essential that the lateral displacement of sheet I0 due to crawling of the sheet on the tilted roll I4 counteract the equal crawl of the sheet in the opposite lateral direction along one or more other tilted rolls, such as the tilted rolls I8, 28 in the herein represented apparatus. All of the unwanted lateral displacement of sheet I0 occurs in the approach to the second and subsequent tilted rolls. In the illustrated embodiment, all of the unwanted lateral displacement occurs in the two portions Illa and Ifib of sheet I0 travelling, respectively, from the fixed guide roll 26 to the second tilted roll I8 (Fig. 4), and from the fixed guide roll 28 to the third tilted roll 20 (Fig. 5). The amount of this unwanted lateral displacement is proportional to the perpendicular distance between the plane of the axes of the fixed guide rolls, from which the sheet passes to the second and subsequent tiltable rolls, and the plane of the axes of the second and subsequent tiltable rolls when the latter are in their neutra1 positions. This perpendicular distance is indicated at B in Fig. 1 of the illustrated embodiment wherein the two said planes of the roll axes are horizontal although they may be otherwise disposed.

According to my invention, the fixed guide roll, or rolls, from which sheet I0 travels to the second tiltable roll, or to the second and subsequent tiltable rolls, is or are located to one side of the plane of the neutral axes of the tiltable rolls, and sheet I0 is guided to the first tiltable roll from a lead-on guide roll which is located to the opposite side of the said plane of the neutral axes of the tiltable rolls. All of the counteracting corrective crawl of sheet I0 occurs as the sheet approaches the first tiltable roll after engaging around the lead-on guide roll, and the amount of corrective crawl of sheet I0 along the first tiltable roll, when tilted, is proportional to the perpendicular distance that the axis of the lead-on guide roll is located from the said plane of the neutral axes of the tiltable rolls. In Fig. 1 of the illustrated embodiment, the axis of the lead-on guide roll I2 is located a perpendicular distance A from the plane of the neutral axes of the tiltable rolls I4, I8 and 20, and Fig. 3 illustrates the counteracting corrective-crawl effect when the first tiltable roll M is tilted. Hence, in the illustrated embodiment, since all of the rolls I 4, I8, 20 will have equal tilt, the total amount of unwanted crawl of the sheet portions IOa, [0b to the right along the tilted rolls I8, 20, as in Figs. 4 and 5, is anticipated and counteracted by the crawl of the sheet to the left along the first tilted roll I4, as in Fig. 3. This result is achieved and maintained because the axes of the guide rolls 26, 28, 30 are located to one side of the plane of the neutral axes of the tiltable rolls a distance B equal to one-half the perpendicular distance A that the axis of the lead-on guide roll I2 is 10- cated to the opposite side of the said plane of the neutral axes of the tiltable rolls. If only two tilted rolls [4, 18 were to be employed, instead of the three as herein illustrated, the lead-on guide roll l2 would be shifted to its dotted position I2 of Fig. l and the sheet then would leave the apparatus from the fixed guide roll 28, as suggested by the dotted representation of the sheet l9 leaving roll 28 in Fig. 1. In other words, the distance that the axis. of lead-on roll l2 is'located from the plane of the tiltable roll axes, in their neutral positions, should be equal to the distance that the axes of the guide rolls 26, 28, etc. are located from the said plane of the tiltable roll axes, in their neutral positions, multiplied by one less than the total number of tiltable rolls l4, l8, etc. that are employed.

Hence, referring to Fig. 1, and assuming a pre determined tilting of rolls I4, IB and 2t, sheet ill will leave the weft straightening apparatus in a path substantially in alignment with its path of approach to lead-on roll l2 when A=2B wherein 2 is one less than the number of tiltable rolls employed. The following formula, wherein m is the number of tiltable rolls employed, is applicable in all cases: A=(:c-1)B.

It does not matter how far the lead-on roll i2 is located from the initial tilted roll H in the direction from which sheet I is coming so long as the sheet has sufiicient wrap around the initial tilted roll I4 to avoid slip of the sheet on the inclined roll.

The plane of the axes of the tiltable rolls l4, i8, 20, when the tiltable rolls are in their neutral positions of Figs. 1 and 2, is herein sometimes called the neutral plane and also the plane of the neutral axes of the tiltable rolls.

The invention solves a long existing troublesome problem in the weft straightening art and eliminates the need for the relatively expensive sheet guiding mechanism which heretofore has been requisite for restoring a laterally displaced sheet to its proper path.

It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

I claim as my invention:

1. Tiltable roll weft straightening apparatus comprising a series of generally parallel staggered rolls of which at least one has its axis fixed in a predetermined plane and a plurality of others have their axes in another plane which is generally parallel to and spaced a substantial distance from the first mentioned plane, the latter said rolls being mounted for tilting in unison toward the first mentioned plane, all of said rolls being adapted to be rotated by a travelling sheet engaged alternately over said tiltable rolls and said fixed axis roll, and a lead-on roll having its axis generally parallel to said fixed-axis roll and spaced from the said plane of the tiltable roll axes, in the neutral position of the tiltable rolls, a distance equal to the perpendicular distance between said two planes multiplied by one less than the number of said tiltable rolls, said spacing of the lead-on roll and fixed-axis roll being to opposite sides of said plane of the tiltable roll axes, in the neutral position of the tiltable rolls, with said lead-on roll located for guiding said sheet to the nearer tiltable roll with sufiicient wrap of the sheet around the latter to maintain the sheet against slipping thereon when the tiltable rolls are tilted.

2. Tiltable roll weft straightening apparatus comprising a series of generally parallel staggered rolls of which one plurality have their axes fixed in one common plane and another plurality have their axes in another common plane which is generally parallel to and spaced a substantial distance from the first mentioned common plane, the latter said rolls being mounted for tilting in unison toward the first mentioned common plane, said rolls being adapted to be rotated by a travelling sheet engaged alternately over said tiltable rolls and said fixed-axis rolls, and a lead-on roll having its axis generally parallel to said fixed-axis rolls and spaced from the said common plane of the tiltable roll axes, in the neutral position of the tiltable rolls, a distance equal to the distance between said two common planes multiplied by one less than the number of said tiltable rolls, said spacing of the lead-on roll and fixed-axis rolls being to opposite sides of said common plane of the tiltable roll axes, in the neutral position of the tiltable rolls, with said lead-on roll located for guiding said travelling sheet to the nearer tiltable roll with sufficient warp of the sheet around the latter said roll to maintain the sheet against slipping thereon when the tiltable rolls are tilted.

3. In a tiltable roll weft straightening apparatus having a plurality of tiltable rolls whose axes are parallel and tiltable in unison out of a neutral plane to straighten skewed weft threads of a travelling textile sheet having a predetermined proper path of travel entering and leaving the apparatus which is perpendicular to the axes of said tiltable rolls when in their said neutral plane, the combination with said tiltable rolls of at least two fixed-axis guide rolls having their axes parallel to each other and to the tiltable roll axes when the latter are in their said neutral plane, one of said fixed-axis guide rolls being a lead-on roll located to one side of said neutral plane of the tiltable roll axes, and at least one other of said fixed-axis guide rolls being a transfer roll located to the opposite side of said neutral plane of the tiltable roll axes and in staggered relation to the first and second of said plurality of tiltable rolls, said fixed-axis lead-on roll being positioned and adapted to guide said travelling sheet to said first tiltable roll whence the sheet passes to and around said fixed-axis transfer roll and thence to and around said second tiltable roll, whereb lateral crawl of the sheet in one direction along said second tiltable roll, due to any particular angle of tilt of the said tiltable rolls, is counteracted by an induced lateral crawl of the sheet in the opposite direction along said first tiltable roll.

4. Weft straightening apparatus comprising a plurality of generally parallel tiltable rolls mounted for tilting in unison in either direction about a common axis, the common plane of the axes of said rolls when the rolls are in their neutral nontilted position being herein called the neutral plane, a lead-on roll having its axis fixed in general parallelism with the axes of said tiltable rolls when the latter said axes are in said neutral plane, the axis of said lead-on roll being spaced a predetermined distance to one side of said neutral plane and spaced a substantial distance from said tiltable rolls in that general direction from which a sheet to be acted upon comes to the apparatus, a plurality of generally parallel guide rolls having their axes fixed in a common plane which is generally parallel to and spaced a predetermined distance to the other side of said neutral plane with said fixedaxis guide rolls in staggered relation to said tiltable rolls, a said sheet to be acted upon being engaged over said lead-on roll and passing thence to and around the nearer one of said tiltable rolls on a course which takes the sheet back and forth around said tiltable rolls and said fixed-axis guide rolls in alternating succession. the distance the axis of said lead-on roll is spaced from the said neutral plane being equal to the distance that the plane of the axes of said fixed-axis guide rolls is spaced from said neutral plane multiplied by one less than the number of said tiltable rolls around which said sheet is engaged.

5. Tiltable roll weft straightening apparatus comprising a series of generally parallel rolls of which the axes of one plurality are fixed in one common plane and the axes of another plurality are in a difierent common plane herein called the neutral plane which is generally parallel to and spaced a predetermined distance to one side of the first mentioned common plane, the latter said plurality of rolls being tiltable in unison out of said neutral plane in either direction about a common axis thereby to move one end of each tiltable roll closer to the first mentioned common plane and to move the opposite end of each tiltable roll further away from the first mentioned common plane, all of said rolls being in staggered relation, and a lead-on roll having its axis fixed in general parallelism with said tiltable roll axes when the latter are in said neutral plane and spaced a predetermined distance from said neutral plane at that side thereof opposite the side Where said plurality of said fixed axis rolls are located, the distance that the axis of said lead-on roll is spaced from said neutral plane being approximately equal to the distance that said first mentioned common plane is spaced from said neutral plane multiplied by one less than the number of said tiltable rolls which are in use in the apparatus.

6. Weft straightening apparatus comprising a. plurality of rolls in each of two generally parallel planes which are spaced a predetermined distance apart, all of said rolls having their axes generally parallel when in said planes and one of said plurality of rolls having their axes fixed in one of said planes and in staggered relation to the other plurality of rolls whereby a travelling textile sheet may engage around a roll in one of said planes, herein called the neutral plane, pass to and around a roll in the other plane and back and forth into alternating engagement around successive rolls at each of said planes, the plurality of rolls at said neutral plane being tiltable in unison out of said neutral plane to move one end of each tiltable roll closer to the other said plane, a lead-on guide roll in position to be engaged by said sheet as the sheet travels toward said staggered rolls and adapted to guide the sheet to the nearer one of said tiltable rolls, said lead-on roll having its axis generally parallel to the axis of all of said staggered rolls when said staggered roll axes are in said two planes, and said axis of the lead-on roll being spaced from said neutral plane a distance approximately equal to the distance between said two planes multiplied by one less than the number of tiltable rolls employed in the apparatus, whereby said sheet leaves the apparatus in a path approximately aligned with its path of approach to said lead-on guide roll.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,404,110 Gigliotti Jan. 17, 1922 2,311,674 Lilja Feb. 23, 1943 2,343,328 Robertson Mar. 7, 1944 2,461,084 Robertson Feb. 8, 1949 2,492,737 Dunn Dec. 27, 1949 

